6FA2C H9
MIDI for the Computerphile Page 1
8
A MIDI Primer for Computerphiles
In the course of pursuing my dual interests in music and
computers, I've noticed one thing: though "crossover" in these
two fields is certainly evident in hardware and software, most
computer folk seem to know little about what those weird musician
types are doing with their digital machines, and musicians, well,
many musicians still think a byte is something you go out for
after playing a set. Hopefully, this report will be of some use
to computer people who would like to know something about the
computer revolution which has swept the music industry, but don't
know where to start. Obviously, this is a very large topic, and
I can only present the broadest outlines here. If there is
sufficient interest, more detailed reports will follow.
A Basic Definition and a Little History
MIDI (Musical Instrument Digital Interface) is a
communications protocol developed jointly by American and
Japanese manufacturers of electronic musical instruments. It is
a defined standard administered by an independent association,
the International Midi Association, and, at least theoretically,
assures compatibility among equipment produced by different
manufacturers. In practice, the ideal of total compatibility is
not always achieved, but at least "MIDI standard" has a little
more meaning than "RS232 standard interface".
Now for a little history. MIDI is a fairly recent
innovation; the standard was first proposed in 1981, when,
fortunately, it was realized that unless someone did something,
chaos would prevail in the musical instrument industry (with, of
course, the resultant loss of sales. Never forget that MIDI was
spawned by manufacturers, not by users. More on this later.)
Over the past 15 or 20 years, many electronic instruments
have been introduced. Keyboard synthesizers are examples that
are probably familiar to most people. These machines were analog
devices -- the pitch of the sound they produced was determined by
a linear-scaled control voltage generated by the keyboard. With
the advent of microprocessors, it became feasible to produce
digitally controlled instruments, eliminating the inherent
instability and inaccuracy of the analog control approach.
Please note, that the terms digital and analog are used here only
to describe the method of control; they have a totally different
meaning when applied to the technique used to generate the sound.
That will be discussed in the section on Hardware. Anyway, what
is important is that instead of keyboards that produced varying
voltages, you now have keyboards that produce discrete codes,
just like a computer keyboard.
Now I must digress for a moment, and present a short
discussion on the elements of tonal music. Tonal music (as
Copyright 1987 by Paul Tauger. This article may be freely
exchanged, copied and/or distributed provided it is done without
charge.
9
MIDI for the Computerphile Page 2
8
distinguished from atonal music, i.e. noise) can be described as
constituting three determinant parameters:
1 - Notes (comprised of pitch and harmonic data)
2 - Volume (how loud or soft the sounded note is)
3 - Duration (how long the note is sounded)
A digitally-encoded keyboard is capable of generating, as a
discrete quantity, only one of the 3 parameters. Notes are
determined by which key is pressed. However, duration can be
determined by measuring how long the key is pressed against a
known time base. Volume is a little tougher; you can measure the
pressure with which the key is hit, but that will necessarily
require analog measurement. However, if you measure the time
between the moment the key begins to be depressed and the moment
it is fully depressed, you will know how fast the key is
travelling, which gives a good indication of how hard it was
struck. This measurement, (beginning of key travel - end of key
travel/time) is called "velocity" and provides the third
parameter. (Some MIDI instruments use analog pressure
measurements to generate velocity data).
If these three parameters were recorded in real-time, and
then transmitted to an instrument, it would be possible to
reproduce the original performance exactly as the musician played
it. This technique offers a major advantage over analog
recording technology: there is none of the degradation of sound
which is inherent in any analog recording process. The first
devices which attempted to store and reproduce these parameters
are familiar to everyone: the old-fashioned player piano
captured key presses in real-time and stored them on paper piano
rolls for later retrieval. The evolution of electronic
instruments resulted in various schemes to electronically store
these parameters. However, the early attempts at "sequencing"
(the process of coding, storing and retrieving note, volume and
duration data) were individually developed by each manufacturer
-- compatibility between different brands of instruments was rare
(nonexistent).
The MIDI standard was originally proposed to provide a
single standard to be used by all instrument manufacturers, so
that varied and different instruments could function together.
However, as will be shown later, MIDI has evolved considerably
beyond a basic note definition "language".
A Little Technical Data
I won't reproduce the full standard here because it is
readily available from a variety of sources and is not necessary
for understanding the basic principles and applications of MIDI.
MIDI is a synchronous digital protocol. Data is sent in 8-bit
words at 31.2K baud using a current loop. Why yet another
format, when good ole' RS232 is sitting there on just about every
Copyright 1987 by Paul Tauger. This article may be freely
exchanged, copied and/or distributed provided it is done without
charge.
9
MIDI for the Computerphile Page 3
8
computer in existence? The official Party Line is: RS232, with
its top speed of 19.2K is too slow to handle all the note data.
Current loop is necessary to suppress interference that would
result from the long cable runs. Could it be an excuse to sell
more hardware? Hmmmmmm. Anyway, back to facts. MIDI protocol
consists of control and data words which may be from 1 to 3 bytes
long, or, in certain situations, longer. MIDI defines the three
parameters from the previous section as follows:
NOTES: 128 notes are defined, from 0 to 127. Notes
follow the standard even-tempered chromatic scale.
Notes are NOT defined as specific frequencies,
permitting performers to tune their instruments as
required.
VOLUME: The primary means of specifying volume is
velocity (see previous discussion). Velocity is
quantized per note in discrete steps from 0 (softest)
to 127 (loudest). There are also other parameters
which control relative volume of the entire instrument.
DURATION: MIDI handles duration of notes with two
parameters: NOTE ON and NOTE OFF. NOTE ON is
generated when the key is pressed, NOTE OFF is
generated when the key is released. These two commands
are sent independently of each other; if a NOTE ON is
issued and a corresponding NOTE OFF is not sent
(because of data errors, mechanical failures, or poor
programming) the note will sound forever (or until the
instrument is turned off). This presents occasional
problems, particularly in live performance, because, as
in any communications protocol, data errors do
sometimes happen. MIDI does provide an "All Notes Off"
command.
As stated before, duration must be measured against a known
time standard. MIDI provides a MIDI clock signal, which is sent
as a specifically designated data byte. MIDI divides each
musical beat into 128 MIDI clocks. MIDI also defines the
following parameters:
PROGRAM CHANGE: This parameter selects different
"patches" or sounds in the musical instrument. The
programs are numbered 0-127. Note that the patches
themselves are not defined by the MIDI standard.
Program #32 might be a violin on one synthesizer and
barking dogs on another.
CHANNEL: MIDI provides for 16 different channels.
Most MIDI commands and data can be specific to a single
channel, i.e. instrument, or can be global.
Copyright 1987 by Paul Tauger. This article may be freely
exchanged, copied and/or distributed provided it is done without
charge.
9
MIDI for the Computerphile Page 4
8
PITCH BEND: As the name implies, the pitch of the note
can be "bent" up or down in real time (remember Jimi
Hendrix?).
MODULATION: This is a control parameter that usually
effects the vibrato sound of the note, though some
instruments can be programmed to use modulation data to
control other parameters. Modulation and Pitch Bend
are usually controlled from the instrument with wheels
or levers that the performer can rock back and forth.
SUSTAIN: The same as the sustain pedal on a piano, it
will cause the note to sound until the pedal (or other
control device) is released.
The MIDI spec allows for 127 different control parameters,
although only a small number are currently identified and
standardized. In addition, MIDI provides a "system exclusive"
message. Each manufacturer is assigned their own unique "sys ex"
code which allows them to implement custom features without
interfering with other manufacturers customizations. Ah ha! you
say, doesn't that defeat the purpose of a "standard"? Yes, to an
extent it does, but remember it was the manufacturers of the
equipment who pushed for a standard, and allows for innovation
and differentiation between brands. And, as stated earlier, you
must admit that this standard is considerably more consistent
than a "standard" RS232 interface.
The preceding constitutes only the broadest description of
the MIDI protocol, and there are quite a few more features which
I haven't covered here. However, you should have a general idea
of the kinds of data MIDI can handle. Now I'll tell you some of
the ways MIDI is used.
What is MIDI Used For?
Ok, we've established that MIDI is both a communications
protocol and note definition language. What can it do?
1. Control of Instruments
Any musical instrument can be thought of as having two
distinct components: the sound producing component and the
control component. As an example, the keyboard of a piano, the
frets on a guitar and the buttons on a clarinet can all be
thought of as control components. The piano's strings and
hammers, the guitar's strings and acoustic body (or magnetic
pickups if it is electric) and the clarinet's reeds and hollow
body are all sound producers. The first application for MIDI
permits the separation of control and sound production
components. The most common (though not the only) MIDI
controller is the keyboard. The keyboard generates the NOTE ON
and NOTE OFF data as well as various other control data (see
Copyright 1987 by Paul Tauger. This article may be freely
exchanged, copied and/or distributed provided it is done without
charge.
9
MIDI for the Computerphile Page 5
8
previous section) and passes it on to the sound producing
section. The sound producing section could be a synthesizer,
digital sampler, drum machine, or any other MIDI equipped sound
producing device. Most synthesizers combine the sound producing
device and the keyboard controller in a single physical package.
However, MIDI permits them two be addressed as two distinct and
separate sections.
A single musician at a single keyboard can play many
different instruments simultaneously. There are two ways of
doing this. The first places several different sound producers
on the same channel, all responding to the same MIDI data at the
same time. This is a process called "layering" and can be used
to produce full, rich, harmonically complex sounds. The effect
is of several different instruments all playing in unison.
The second technique is called "splitting" the keyboard --
arbitrarily assigning specific channels to specific notes on the
keyboard. This permits different instruments to play different
music, all under the control of one musician at one keyboard. As
an example, the musician might assign the bottom two octaves of
the keyboard to channel 1 and the rest of the keyboard to channel
2. If a digital sampler set to reproduce the sound of a bass is
assigned to channel 1, and a synthesizer producing a piano sound
is assigned to channel 2, the musician will be able to play the
bass line accompaniment with his left hand while playing the
piano lead with his right.
Note that when instruments are layered, an unlimited number
of instruments may be played. However, when the keyboard is
split, the maximum number of instruments that may be controlled
is limited to the maximum number of MIDI channels -- 16.
2. Sequencers
Another obvious application for MIDI is the storing of the
MIDI data stream for later playback -- a process known as
sequencing. This task may be performed either by a dedicated
piece of hardware (called, of course, a "sequencer") or by
general purpose computers equipped with the appropriate software
and interfacing.
Most sequencers allow editing of the MIDI data -- wrong
notes can be corrected, new material can be entered one note at a
time, and sections can be rearranged, moved or copied (much like
a word processor). Almost all sequencers allow for transposition
(changing key) and tempo changes. Some will "auto-correct" so
that all notes are played exactly on the beat, eliminating any
sloppiness in playing.
Since MIDI provides 16 unique channels, 16 different
instruments can be controlled simultaneously, allowing the
sequencer to function like a multi-track tape recorder. Each
instrument is "played" into the sequencer individually on a
Copyright 1987 by Paul Tauger. This article may be freely
exchanged, copied and/or distributed provided it is done without
charge.
9
MIDI for the Computerphile Page 6
8
different channel. When all the parts have been entered, the
sequencer can play them back all at the same time, in effect
creating a one-man band (or one-man philharmonic orchestra).
Finally, since MIDI was developed as a professional and
semiprofessional musical tool, several features required for
recording are supported. Most sequencers allow for some form of
tape sync. In the most basic form of tape sync, the sequencer
provides a synchronization signal which can be laid down on one
track of a multi-track tape recorder. When new tracks are laid
down, the sequencer can synchronize to the previously recorded
material. This makes multi-track recording, over-dubbing, and
similar recording tricks much easier. The MIDI spec also defines
a MIDI SONG POINTER, which can be thought of as "mile markers" in
the music. A sequencer that supports MIDI SONG POINTERS is
capable of automated punch-in and punch-out -- the process of
inserting new material into a previously recorded track.
3. Librarian Software
One of the uses manufacturers of MIDI instruments make of
the SYSTEM EXCLUSIVE command is for data dumps; literally
"dumping" all the parameter data needed to define sounds and
setups out the MIDI line on command. Software that stores this
data for later recall is called Librarian software. Most
librarians are not limited to merely storing and retrieving the
dumped data, but are also capable of editing specific patch
parameters -- a task which is more easily performed on a computer
with a full keyboard and video display than on the more limited
displays and entry devices available on the synthesizers
themselves.
A special form of librarian, generally called a Sound
Modeling Program, use the SYSTEM EXCLUSIVE dump command to obtain
wave sample data from digital samplers (see the section on
Hardware). The wave sample can then be displayed, manipulated,
stored and retrieved by the librarian. "Serious" sampling with
digital samplers virtually mandates the use of some form of Sound
Modeling Program.
4. Notation Software
Notation software takes the MIDI note data and translates it
into conventional music notation which can be displayed on the
screen or printed on a dot matrix or laser printer. It allows a
musician to play music in on the controller keyboard in real time
and get finished musical scores out. Alternatively, music can be
entered in notational form on the computer keyboard using
wordprocessor-like commands, and the finished result can be heard
played on a MIDI equipped synthesizer.
Copyright 1987 by Paul Tauger. This article may be freely
exchanged, copied and/or distributed provided it is done without
charge.
9
MIDI for the Computerphile Page 7
8
5. Other Applications
Lately, MIDI has also found application in non-musical
functions, e.g. controlling mixing boards, stage lighting and
sound processing equipment (reverbs, digital delays, etc.).
Problems with MIDI
As powerful a tool as MIDI is, it is not totally without
problems. What follows are a few cautionary notes:
1. As already mentioned, MIDI defines note duration with two
separate data commands: NOTE ON and NOTE OFF. The possibility of
a NOTE ON being transmitted without a corresponding NOTE OFF
following is an always present danger. Data can get garbled
during transmission, lines become unplugged (the MIDI standard
utilizes 5-pin DIN connectors which have a nasty habit of
loosening in their sockets), channels accidentally get switched,
etc. Without a NOTE OFF command, the note will continue to sound
for ever. This can be a major annoyance in a recording session
(more than annoying if it occurs during that once-in-a-lifetime
hot set) and in live performance, well, you get the idea.
Various manufacturers have come up with different solutions to
the problem, the most common being a button which, when pressed,
produces an ALL NOTES OFF command. This will, of course, silence
the offending note, but silences all the other notes in the
process. Because the two note NOTE ON/NOTE OFF structure is
intrinsic to the MIDI spec, we will just have to live with the
occasional stuck note.
2. MIDI transmits at 31.2k baud. A little math shows that MIDI
is capable of sending approximately 1000 notes per second. This
is obviously more than any musician can ever play. However, when
you divide this capacity among 16 channels, add in the data
stream produced by controllers such as pitch benders and
modulation wheels, then throw in a few program changes for good
measure, you have the possibility of overrunning the data. To be
honest, I've never heard of this happening, but the possibility
is still there.
3. Most MIDI instruments contain a MIDI-in jack for receiving
data, a MIDI-out jack for transmitting data, and a MIDI-thru jack
for passing MIDI data along to another instrument. When
instruments are daisy-chained together, a perceivable delay
develops between the first and last instrument in the chain.
This is the infamous "MIDI delay" of which you may have heard.
This delay can be eliminated by using a device known as a "MIDI
Thru Box". This is an active splitter that accepts one MIDI
input and divides it into 4,6 or more MIDI outputs, thereby
assuring that all instruments receive the MIDI signal at the same
time. Does it solve the problem? You bet! Does it cost more
money? You bet!
Copyright 1987 by Paul Tauger. This article may be freely
exchanged, copied and/or distributed provided it is done without
charge.
9
MIDI for the Computerphile Page 8
8
4. Another problem, frequently mistaken for MIDI delay, is
inherent in some MIDI synthesizers. Remember that the keys on
the keyboard are scanned sequentially, in the same manner as a
computer keyboard. In some brands of keyboard synthesizers, the
internal electronics introduce their own delays in translating
the key presses into sounds. Though not specifically a MIDI
problem, it is a problem none the less, and is particularly
evident when the musician "grabs" large chords consisting of many
notes. Fortunately, this problem is recognized as a hardware
"bug" and is usually corrected by the manufacturer (after enough
people complain).
5. By its very nature, MIDI is designed to permit one controller
on line at a time. More than one controller on line will result
in inevitable data collisions with the resultant garbling of
data. Think of two computers sending data to two printers at the
same time. There are devices available which mediate data
contention between two MIDI controllers. Generally called Midi
Mergers, they are another relatively expensive solution to what
seems like a simple problem.
6. Though the MIDI protocol is clearly defined in the spec,
computer storage schemes are left up to the individual software
producer. There is no MIDI equivalent of an ASCII or EBDIC file.
Consequently, MIDI data files produced by one piece of software
can not be read by another. This would be fine if there were
such a thing as a program that did everything (and did it well).
However, as in the case of the "integrated" packages that
combined word processors, spread sheets, data bases and
communications software all in one box, such as thing simply
doesn't exist. Right now, the only way to exchange MIDI data
between programs is by transmitting the data over a physical MIDI
data line between two computers.
7. As mentioned earlier, the MIDI spec provides considerable
latitude to manufacturers who want to incorporate custom features
in their instruments. Consequently, MIDI is afflicted with
"creeping non-standardization". There are already controller
number conflicts between some of the largest instrument
manufacturers, and the SYSTEM EXCLUSIVE command guarantees that
no single librarian program will work with all synthesizers.
8. Now for what I see as the major problem with MIDI - MONEY!
Until the electronic revolution, quality musical instruments were
carefully crafted, often handmade, and very expensive. After
all, great instrument making is an art. Consequently, musicians
have become accustomed to paying a lot of money for the
instruments they play. This tradition has been maintained by
many manufacturers of mass-produced electronic instruments.
There are exceptions (see the description of the Casio CZ-101 in
the Hardware section), but for the most part, the sales price of
a piece of electronic musical gear frequently does not bear any
correspondence to the cost of its manufacture. Fortunately, the
current trend is towards dropping prices. However, walk into any
Copyright 1987 by Paul Tauger. This article may be freely
exchanged, copied and/or distributed provided it is done without
charge.
9
MIDI for the Computerphile Page 9
8
music store and you will see MIDI cables (2 DIN plugs and 10 feet
of 2 conductor shield cable) for $25 or more. Though good MIDI
software tends to be very expensive, it should be remembered that
MIDI software publishers have a much more limited market for
their product than publishers of more common business-oriented
packages.
A Brief (and Biased) Hardware Catalog
I would like to conclude this report with a description of
the types of MIDI hardware currently available. Hardware
selection is a very personal decision, and what I say here
(beyond the basic descriptions) is necessarily biased by my own
preferences. Here goes:
1. Sound Producing Devices
The devices which produce the actual sounds can be divided
into two basic categories:
- Synthesizers - devices which generate basic sound
waveforms, and, by manipulating various parameters of
the sound (envelope, modulation, etc.) can produce a
diversity of tonal textures and colors.
- Samplers - devices that digitally record, or sample,
a sound, and then play it back at pitches determined by
the controller.
Synthesizers can be divided into two broad categories.
Analog synthesizer use conventional oscillators and filters to
produce different sound waveforms, e.g. sine waves, square waves,
triangle waves, etc. Digital synthesizers "store" a digitally
encoded waveform in ROM, and produce their sounds by reading the
waveform out to D-to-A convertor. Generally, analog synthesizers
are thought of as producing "warmer" sounds than their digital
counterparts. Some common synthesizers are:
Yamaha DX-7 (approx. $1700) - The DX-7 has become something
of a "standard" for digital synthesis, and is used by many
professional musicians. Most librarian software supports
this machine.
Casio CZ-101 (approx. $300) - Casio has a complete line of
digital synthesizers, but the CZ-101, in my opinion, offers
more "bang for the buck" than anything else on the market.
This machine is supported by many librarians, is capable of
producing an astonishing range of sounds and is an excellent
"starter" for anyone interested in testing the waters of
electronic music. Two drawbacks: it has a small keyboard
that is difficult to play, and does not support note
velocity; all notes default to a velocity of 64.
Copyright 1987 by Paul Tauger. This article may be freely
exchanged, copied and/or distributed provided it is done without
charge.
9
MIDI for the Computerphile Page 10
8
Samplers are available in a wide range of prices and
capabilities. Factors to be considered in purchasing a sampler:
1 - Sample width. The more bits per sample, the better the
resolution, dynamic range, and fidelity. This rule is not
written in stone, however, as many manufacturers have
developed data compression algorithms that allow them to
squeeze more information out of smaller width samples, and a
12-bit machine may not necessarily sound better than an
8-bit machine.
2 - Sampling rate. Higher sampling rates permit the
reproduction of higher frequency sound data. The Nyquist
rule specifies a sampling rate 2-1/2 times the frequency of
the highest sound to be sampled, i.e. to sample the full
audible audio spectrum (20 Hz to 20,000 Hz), a sampler
should have a sampling rate of (2.5 * 20,000) or 50,000
samples per second.
3 - Number of active samples. The sound of a "real"
instrument can not be reproduced by sampling only one note
and "stretching" it across the entire keyboard. Many
samples taken at many different pitches are necessary to
effectively simulate the distinctive voice of an instrument.
Some samplers provide only a single sample at a time which
must be stretched. Others provide as many as 64 active
samples at a time which may be assigned to specific sections
of the keyboard as needed.
4 - Available memory. Samplers with a lot of memory can
allow higher sampling frequencies, longer samples, and more
active samples.
Digital Samplers are "where the action is" and new machines
are being introduced all the time. Some inexpensive samples of
samplers:
Akai S612 (approx. $1000 with disk storage): The least
expensive "real" sampler (as contrasted with several
sampling toys that have recently hit the market) the S612 is
also available in an expanded version called the S900 for
approximately $3000. The S612 is limited to one active
sample at a time. Sampling rate is also limited, which
restricts its ability to sample high frequency sounds. In
addition, it is a rack-mounted device which requires a MIDI
keyboard to control it. It is, however, a fully implemented
sampler for a minimum price, and constitutes a good
entry-level machine for those who want to experiment with
sampling.
Ensoniq Mirage (approx. $1700 with keyboard): The Mirage is
a versatile instrument that offers a user-selectable sample
rates up to 30 kHz with up to 16 active samples. The machine
also has a full sound modification section consisting of the
Copyright 1987 by Paul Tauger. This article may be freely
exchanged, copied and/or distributed provided it is done without
charge.
9
MIDI for the Computerphile Page 11
8
traditional envelope and filter synthesizer controls,
permitting the user considerable flexibility in customizing
sound samples. Ensoniq offers a large library of factory
samples on 3-1/2" disk (disk drive included with the Mirage)
which range in quality from adequate to extraordinary. A
good test for a sampler is the ability to recreate the sound
of an acoustic piano, as pianos produce extremely complex
waveforms. The Mirage does a very credible job with pianos,
as well as other acoustic instruments. The Mirage is also
available in a less expensive rack mount version (no
keyboard).
Sequential Circuits Prophet 2000 (approx. $2500): 12-bit
sampler with extensive MIDI implementation. Sampling rate
user-switchable up to 41 kHz. There has been some criticism
of the quality of factory-produced library samples, but the
machine is capable of extremely high-quality sampling.
Emu Emulator II (approx. $8000): A very high quality
sampler the uses a proprietary data encoding scheme to
purportedly wring 14-bit resolution out of 8-bit samples.
The Emulator was one of the first "affordable" samplers (as
compared with the $50K - $100K Fairlight and Synclavier) and
has seen extensive use in professional recording and live
performance.
Drum machines are specialized devices that simulate the
sound of a drum set. The sounds are ROM-based digital samples,
though some machines permit the user to sample their own sounds.
All drum machines allow the user to define a number of patterns
which can be strung together to form "songs". A representative
drum machine:
Yamaha RX-15 (approx. $400) - Has 16 different drum sounds
(only 12 available at the same time), memory for up to 99
patterns and 10 songs (depending on complexity). Good MIDI
implementation, though incapable of MIDI sys ex dumps. Also
available as the RX-11 (approx. $700) with complete MIDI
implementation.
2 - Keyboard Controllers
Keyboard controllers produce no sounds by themselves but
generate the MIDI data necessary to control MIDI sound-producing
devices. Keyboard controllers have "actions" that provide a feel
similar to traditional pianos.
MIDI data can also be generated by non-keyboard devices,
including guitars, drums and various wind instruments. Devices
called "pitch riders" can translate an analog sound input into
MIDI data output.
Copyright 1987 by Paul Tauger. This article may be freely
exchanged, copied and/or distributed provided it is done without
charge.
9
MIDI for the Computerphile Page 12
8
3 - Computers
This is a volatile area for discussion, with proponents of
different brands fiercely loyal to their machines (as I am
fiercely loyal to mine - an IBM PC-XT). Anyway, here's a quick
run down:
Inexpensive Machines:
Commodore 64/128: Many software packages are available, as
well as different interface options. The machine's 64K of
memory presents a limitation for sequencing and scoring
programs, but low cost of the Commodores makes for them good
MIDI "starter" systems. If you are considering the
Commodore, avoid software that claims it can use the 64's
internal sound chip to produce "real professional
synthesizer sounds". The sound chip on the 64 is quite
clever and very versatile, but is limited to three voice
polyphony and has severely restricted sound modifying
capabilities. It is not a substitute for a synthesizer by
itself. Passport and Dr. T are two publishers of quality
MIDI software for the Commodore.
Low-cost Atari's: Same limitations as the Commodore, though
perhaps with fewer quality software packages available.
Noted exception: Hybrid Arts produces well recognized and
well respected software, though unfortunately, only for the
Atari line.
Apple II - About on a par with the cheap Atari's from a
music standpoint. 48K memory presents severe limitations.
Moderately Priced Machines:
Only two worth considering - the Amiga and the Atari ST.
The Atari has slightly more software packages available and
offers a built-in MIDI interface. The MIDI interface is an
extra-cost option on the Amiga. I'll avoid jumping into the
Atari vs. Amiga war by saying both machines offer good value
and are well-suited for MIDI and other music applications.
More Expensive Machines:
Macintosh: In fairness, I must confess to a certain amount
of anti-Mac prejudice. My criticisms are not new:
expensive peripherals, up-until-recently closed
architecture, hard-to-support serial bus, operating system
designed for computerphobes, etc. However, if you like it
you like it, and there are some excellent professional music
packages available for it. However, my preference, hands
down, is:
IBM PC-XT (and PC clones): The PC offers a great variety of
powerful, professional music software packages, and a
Copyright 1987 by Paul Tauger. This article may be freely
exchanged, copied and/or distributed provided it is done without
charge.
9
MIDI for the Computerphile Page 13
8
variety of flexible MIDI interfaces are available for it.
It is also the only machine which will run Personal
Composer, the only notation program I've seen which actually
works. There are other notation programs out, but they are
so riddled with bugs as to be almost unusable, or else are
so limited in their implementations as to impose severe
restrictions on composers. (I will happily retract the
preceding statements upon compelling evidence to the
contrary). One program worth mentioning is Texture, a
sequencer which has become the de facto standard of
professional musicians.
Final Words
As stated at the outset, MIDI is a very large topic to be
tackled in a single report. I hope I have presented enough
information to give the MIDI neophyte a basic understanding of
the topic. Let me also remind you that the "review" material
presented here is highly subjective, particularly in the
"hardware" section. There are many more fine instruments and
software packages which I have not mentioned here.
A good source for information on MIDI and electronic music
in general is KEYBOARD magazine, which publishes reviews of
hardware and software, features on all aspects of keyboard music
(both acoustic and electronic), occasional how-to articles, etc.
I hope some of you who read this will be motivated to
experiment with MIDI. The control capabilities of sequencers and
the sound generating abilities of the various synthesizers and
samplers put the ability to create professional sounding music in
the hands of almost anyone. If there is enough interest, I can
prepare occasional reports that explore specific areas of
electronic music production in greater detail. Messages for me
can be left at The Sleepy Hollow BBS, 213-859-9334 (24 hours,
1200 baud, 8-bit, no parity, 1 stop bit), which, incidentally, is
the finest BBS I've encountered and is run by a knowledgeable and
dedicated Sysop.
Copyright 1987 by Paul Tauger. This article may be freely
exchanged, copied and/or distributed provided it is done without
charge.
9